The objective of this research is the understanding of visual function in terms of the underlying membrane events in retinal neurons. The research will proceed in a hierarchical order, beginning with an analysis of membrane conductances in individual cells that account for cellular behavior, then building an understanding of cellular network behavior through an analysis of synaptic function. Finally we hope to be able to account for retinal visual function by analyzing cell and network interactions. The membrane currents underlying cellular and synaptic activity will be analyzed using the newly developed methods of whole cell patch clamp technology applied to living retinal slices and enzymatically-isolated cells. Our preliminary results indicate that these techniques allow a much greater resolution of recording and cause less cell damage than conventional methods. Using these methods, each retinal cell-type now appears to utilize a variety of active currents in processing the visual message, currents obscured earlier by the damaging effects of conventional recording. These studies will provide specific information about the ionic basis for individual cell function, a better understanding of synaptic function in the unique graded-potential synapses of the retina, the role of specific transmitter sybstances in mediating cellular communication, and the propagation of signals through lateral retinal networks.